1. Field of the Invention
The invention described herein relates to medical assessment. In particular, the invention relates to early detection of potential dysfunction.
2. Background Art
Current methods for detecting a patient""s susceptibility to stroke are well known, but tend to be costly and/or invasive. Examples include positron emission tomography (PET) and the use of sonogram technology to image capillaries in the brain. At the same time, a considerable amount is known about strokes, and about how and why they occur. It is well known that a stroke can preceded by changes in blood flow in the brain. It is also well known that these changes can occur well in advance of the stroke, sometimes appearing months beforehand. Blood flow may be diminished in a blood vessel, for example, as a result of plaque build-up in the vessel. Moreover, this can lead to the generation of capillaries to compensate for the decreased blood flow in the original blood vessel. Plaque build-up may continue to the point of complete blockage, leading to a stroke. Alternatively, a sudden dislodging of the plaque can bring a sudden increase in blood flow to the newly developed capillaries, which can also lead to a stroke.
While such phenomenon are well understood, the only methods currently available for detection of changes in neural blood flow are costly. Such detection methods are therefore used judiciously; more widespread use would be prohibitively costly. As a result, strokes are not always anticipated. Hence, there is a need for a non-invasive and relatively inexpensive method for detecting a person""s susceptibility to stroke.
The invention described herein is a method and apparatus for facilitating assessment of a patient""s susceptibility to stroke. The method begins with the step of collecting electrical signals from the brain of the patient under assessment. Signal data corresponding to the collected electrical signals is then compared to at least one standard. In an embodiment of the invention, the standard represents a neural electrical signal taken from a person known to be susceptible to stroke. A positive comparison result suggests susceptibility of the patient under assessment to stroke. Moreover, the comparison result can be used to characterize the pattern of neural blood flow and the degree of susceptibility to stroke. A strong similarity to a standard taken from another patient of known susceptibility suggests that the patient under assessment is experiencing similar neural blood flow and is susceptible to stroke to a similar degree. This information, in turn, can be used to determine the both the need for additional testing and/or the appropriate type and extent of therapy. In another application, this information can be used in categorizing the patient for purposes of determining enrollment in clinical trials.
In an alternative embodiment of the invention, the standard represents a neural electrical signal taken from the patient under assessment at an earlier point in time. A positive comparison in this case suggests that the condition of the patient under assessment has not changed. A negative comparison result suggests that the neural electrical activity of the patient under assessment has changed, implying possible changes in neural blood flow. This in turn can suggest susceptibility to stroke and the need for additional tests and/or for pharmaceutical or other therapeutic treatment. The apparatus for collection of electrical signals from the brain includes a headcap with electrodes concentrated in an area corresponding to a particular cranial region of interest.